Carbon-brush holder for dynamo-electric machines and motors



(No Model.) 2 Sheets-Sheet 1.

J. J; WOOD. CARBON BRUSH HOLDER FOR DYNAMO ELECTRIC MACHINES AND MOTORS.

Patented Nov. 22, 1892,.

FIG. I.

I II 8 I l I P I! I I 3 K INVENTOR:

By, his Azl'omeys, WL f@o Tu: NORRIS PETERS 00., PHoTou'mo WASHINGYDN,uv c.

(No Model.) 2 SheetsSheet 2'.

J. J. WOOD. CARBON BRUSH HOLDER FOR DYNAMO ELECTRIC MACHINES AND MOTORS.

No. 486,656. Patented NOV. 22, 1892..

FIG. 4.

FIG. 5.

By his At/omeys, W dnmm WITNESSESE' NORRIS vzrzns co, 'Fnorauma.WASHINGTON a c V UNIT D STATES PATENT UFFICE;

JAMES J. woon, on FORT WAYNE, INDIANA.

CARBON-BRU8H HOLDER FOR DYNAMO-ELECTRIC MACHINES AND MOTORS.

SPECIFICATION forming part of Letters Patent No. 486,656, dated November22, 1892.

Application filed May 3,1892. Serial No. 431,679. (No model.)

To all whom it may concern:

Be it known that I, J AMEs J. WOOD, a citizen of the United States,residing at Fort Wayne, in the county of Allen and State of Indiana,have invented certain new and use ful Improvements in Carbon-BrushHolders for Dynamo-Machines and Electric Motors, of which the followingis a specifica ion.

This invention provides an improved construction of holders for thecarbon blocks or brushes employed for. taking off the currents from thecommutators of dynamo-electric machines or for conducting the currentsto electromotors. In such carbon-brush holders the carbon block iscommonly held in a guiding-frame, so as to be presented to thecommutator in a plane approximately radialthereto and pressed toward thecommutator by springs.

My invention provides improvements in the construction and mounting ofsuch holders.

Figure lot the accompanying drawings is a side elevator of thecommutator and brushholder yoke and brush-holders of a dynamoelectricmachine or electromotor, the lower part of the yoke and the lower-brushholder being shown in elevation, while the upper part of the yoke isbroken away and the brushholder, carbon brush, and stud are shown invertical section. Fig. 2 is a plan of the upper-brush holder, showing afragment of the yoke in section. Fig. 3 isavertical transverse sectionof the brush-holder cut on the line 3 3 in Figs. 1 and 2. Fig. 4: is aplanof the fixed carbon-holding frame. Fig. 5 is a vertical longitudinalsection thereof on the line 5 5 in Fig. 4. Fig. 6 is. a side elevationof the spring and spring boss or carrier. Fig. 7 is a plan of thelatter.

Referring to Fig. 1, let Adesignate the armature-shaft, B thecommutator, and O the brush-holder yoke. The latter may be mounted inany known or suitable manner. From its opposite ends projectbrush-holder studs D D, as usual. These studs are preferably fixed inthe yoke in the manner shown in Fig 2, where the yoke is shown insection. The portion of the stud passing through the yoke is squared ata and insulated from the yoke by a bushing b. The neck 0 of the stud,being the part to which the terminal socket of the conducting-cable bywhich the current is By the squared brush holder E, carrying the carbonblock or brush F. The brush-holder is constructed with a stationarycarbon-carrying frame .or socket G, which is clamped fixedly on the studD. This frame is'shown separately in Figs. 4 and 5. tion g, which makesa loose and free. [it with the carbon block F and which is carried byarms 7?. .h, projecting from hubs t' 'i, which are clamped upon thestud. Preferably these hubs are split on one side and provided withearsj, which are drawn together by aset-screw to clamp the hubs fixedlyupon the stud. The two hubs are connected by an integral plate or yokeZ.

The carbon brush or block F is inserted in the socket g, its inner endbeing brought against the surface of the commutator. The socket ispartially cut away at one side in or- I der to make room for a leaf orplate spring at,

which is fastened against the socket and the end portion of which ispreferably slitted so as to be subdivided into fingers whichindependently press against the side of the carbon block, therebyforcing it into intimate contact with the opposite side of the socket.The purpose of this spring is twofold-first, to increase the electricalcontact by pressing the block closely against the opposite side of thesocket andby itself making intimate metallic contact with the block,and, secondly, to hold the block firmly but yieldingly in place, so asto prevent its vibration.-

The carbon brush or block is pressed toward the commutator by a spring 5acting against its outer end and serving not only to maintain it inclose contact with the commutator, but also to feed it continuallytoward the latter It consists of a socket poras it is reduced by wear.The tension of the spring'is adjustable by a screw adjustment. Thespringisconstructed,preferably,asaflexible plate fastened at one end toa stationary but adjustable reinforce or carrier, while its other end isin engagement with and presses against the carbon block. Thespring-plate is preferably slitted, so as to divide the latter end intoseparate fingers, each of which adjusts itself independently intocontact with the carbon block, thereby securing an intimate and extendedsurface of contact therewith, so that the spring 5 serves, also, as ameans of conducting the electric current to or from the carbon block.The stationary reinforce or carrier for the spring is preferablyconstructed as an oscillatory eye-block II. (Shown detached in Figs. 6and 7.) It is bored out to make a free working fit with the stud D, andhas the springs screwed firmly against iton one side. It is alsoconstructed with a projecting arm 1), through which passes an adjusting-screw I, the end of which bears against the fixed plate oryokelof the carbon-carrier G. The threads of the screw I engage internalthreads in the arm 1), so that by turning this screw the block orcarrier H is caused to oscillate on the stud, and by turning the screwinwardly the spring-plate 8 may be caused to bear with increasingtension against the outer end of the carbon block. The carrier II andspring .9 constitute, in effect, a lever, of which the stud is thefulcrum, the screw I being the power acting upon the arm 1), while theworking thrustis exerted by the elastic arm 3. The armp is slotted andprovided with a set-screw q, so that when the screwI has been brought tothe proper adjustment it can be clamped fast by tightening the screw g.

In applying this brush-holder, the stud D being already firmly fixed tothe yoke O, the carbon-carrier G and block H are put together and slidover the stud to the proper position, the carrier G being clamped fastto the stud, with the socket g at a suitable distance from the peripheryof the commutator and arranged approximately radially thereof. Thecarbon block may be inserted before or after applying the brush-holderin place. The screw I is then turned to adjust the spring 8 to therequisite tension, and when the proper tension is attained it is setfast by the screw q. As the carbon block wears, the spring 3 presses ittoward the commutator and the tension of the spring is thereby reduced,so that from time to time it requires to be set up by an adjustment ofthe screw I.

The construction shown may be modified in structural detail withoutdeparting from my invention. As shown, the oscillatory block H is keptfrom displacement along the stud by being confined between the two hubsiia construction which is con 'enient and effective, but might besubstituted by some other means for accomplishing the same result. Insimilar manner the construction of the carbon-carrier G with two hubs 'i7: is not strictly essential to my invention.

My invention is advantageous for use when the brush or carbon block iscomposed of several pieces or pencils of square carbon located side byside in the socket in place of one solid block, in which case thefingers of the springs at the side and end bear each against one of theseveral pieces. This construction is found to give a better contactbetween the brush and its holder and the commutator.

I claim as my invention the following-defined novel features andcombinations, substantially as hereinbefore specified, namely:

1. The combination, with a stationarybrush' carrying stud D, ofcarbon-carrier G, fixed on said stud and having carbon-socket g and armZ, a spring 3, oscillatory block II, mounted freely on the stud D, andadjusting-screw I, engaging said block and reacting against said arm Z,whereby the turning of said screw occillates the block II and adjuststhe tension of spring 8.

2. The combinatiomwith stud D, ofcarboncarrying frame G, havingcarbon-socket g and two hubs 't' 2', with spring 5 for pressing thecarbon toward the commutator, oscillatory block H, mounted on the studbetween said hubs, and adjusting-screw I, engaging said block foroscillating it to vary the tension of said spring.

3. The combination, with fixed stud I), of carbon carrying frame G,having carbonsocket g. two hubs i i, fixed on said stud and connectingarm Z, oscillating block II, mounted on the stud between said hubs,spring fixed on said block and pressing on the carbon, andadjusting-screw I, engaging said block and reacting against said arm Zfor oscillating the block to vary the tension of said spring.

4:. The combination, with a brush-holder yoke and stud carried thereby,of a carbon brush holder mounted on said stud, having a spring pressingthe carbon against the commutator and reacting against the stud, so thatit tends to twist the latter, and the stud where it passes through thebrush-holder yoke being constructed with an angular shank a, fitted inan angular hole in the yoke, with an intervening angularinsulating-bushing b and a clamping-screw for tightening it in place.

In witness whereof I have hereunto signed my name in the presence of twosubscribing witnesses.

JAMES J. \VOOD.

Witnesses:

CHAS. O. MILLER, CHAS. A. HARIMAN.

ICC

